Magnetic tripped circuit breaker



April 1966 R. E. LOCHER 3,244,835

MAGNETIC TRIPPED CIRCUIT BREAKER Filed May 14, 1963 FIG-7.1.

l /5 5/ m- W 2 /6 33 T2 lNVE/VTOE 905.551.0015?- BY H/S ATTORNEYS HAze/s, K/ECH, RussELL cfi/(ERA/ United States Patent 3,244,835 MAGNETIC TRIPPED ClRCUlT BREAKER Ross E. Locher, South Pasadena, Calif., assignor to Zinsco Electrical Products, Los Augeles, Calih, a corporation of California Filed May 14, 1963, Ser. No. 280,468 8 Claims. (Cl. 260-88) This invention relates to electrical switches and, in particular, to a manually and externally operable switch suitable for use as a circuit breaker switch. In general a circuit breaker switch is manually or externally actuable for movement between an open circuit or oil condition and a close circuit or on condition and is also automatically movable to another open circuit or tripped condition when certain undesirable conditions exist, the undesired condition usually being excessive current through the switch. After a circuit breaker switch has been tripped or switched to the tripped condition, it is necessary to manually or externally reset the switch to the oil condition before it can again be moved to the on condition.

The very essence of a circuit breaker switch is the automatic movement to an open circuit or tripped condition when undesired conditions such as excessive current passing through the switch are encountered. Accordingly, it is a primary object of this invention to provide a new and improved mechanism for automatically moving the switch to an open circuit or tripped condition when such undesired conditions exist. A further object of this invention is to provide such a mechanism which is extremely simple and reliable and one which provides a relatively high operating force. Another object of this invention is to provide such a mechanism which is extremely swift and efficient in responding to a current overload condition.

It is another object of the invention to provide a circuit breaker switch having an electromagnetic tripping mechanism for moving the switch to the open circuit or tripped condition when a current overload condition exists. Another object is to provide such an electromagnetic tripping mechanism which may be readily incorporated into existing switch designs and one in which the additional parts are easily slid into and removed from the switch case.

An object of this invention is to provide a circuit breaker switch having a first tripping mechanism for substantially instantaneously moving the switch to the open circuit or tripped condition in response to a very high current overload passing through the switch and a second tripping mechanism for moving the switch to the open circuit or tripped condition in response to a high current overload passing through the switch for a predetermined period of time.

Another object of this invention is to provide a circuit breaker switch having an electromagnetic tripping mechanism for substantially instantaneously moving the switch to the open circuit or tripped condition in response to a very high current overload passing through the switch and a thermal tripping mechanism for moving the switch to the open circuit or tripped condition in response to a high current overload passing through the switch for a predetermined period of time.

A further object of this invention is to provide in a circuit breaker switch having a manually actuated off-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position to automatically interrupt the electrical circuit, the combination of a latch release member engageable with the latch to hold the latch in a neutral position, a trip member engageable with the latch release member to move the latch release member out of engagement with the latch, an electromagnetic means for causing the trip member to move the latch release member out of engagement with the latch, and means for energizing the electromagnetic means when a current overload passes through the switch.

A still further object of this invention is to provide in a circuit breaker switch having a manually actuated offon switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position to automatically interrupt the electrical circuit, the combination of a latch release member engageable with the latch to hold the latch in a neutral position, a first trip member engageable with the latch release member to move the latch release member out of engagement with the latch, a conductor passing through the switch mechanism, electromagnetic means for causing the trip memher to move the latch release member out of engagement with the latch including a metal bracket positioned adjacent the conductor so that a current overload passing through the conductor will induce a flux in the bracket, thus causing the bracket to attract the trip member and move it in a direction to move the latch release member out of engagement with the latch, and a second thermal trip member connected to the conductor and engageable with the latch release member to move the latch release member out of engagement with the latch when a current overload passes through the conductor.

Still another object of this invention is to provide an electrical switch including a case, a fixed contact mounted in the case, a moving contact carried on a Contact arm for engagement with the fixed contact, means for moving the contact arm between contact closed and con-tact open positions, means for biasing the contact arm toward a contact open position when the contact arm is in a contact closed position, means engageable with the biasing means for maintaining the contact arm in a contact closed position in opposition to the action of the biasing means, and an automatic circuit breaking mechanism mounted in the case including a latch movable between a neutral position and a circuit interrupted position, the latch releasing the means engageable with the biasing means when in a circuit interrupted position to automatically interrupt the electrical circuit, a latch release member engageable with the latch to hold the latch in a neutral position, with the latch release member biased into engagement with the latch, a trip member engageable with the latch release member to move the latch release member out of engage ment with the latch, an electromagnetic means for causing the trip member to move the latch release member out of engagement with the latch, and means for energizing the electromagnetic means when an overload current passes through the switch.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. The drawing merely shows and the description merely describes preferred embodiments of the present invention which are given by way of illustration and example.

In the drawing:

FIG. 1 is a top elevational view of the circuit breaker switch;

FIG. 2 is a side elevational view with the cover removed showing the switch in the closed position and taken along the line 22 of FIG. 1;

FIG. 3 is a partial view similar to that of FIG. 2 showing the switch in the tripped position;

masses FIG. 4 is a partial sectional view taken along the line 44- of FIG. 2;

FIG. 5 is an exploded View showing certain of the elements which comprise the tripping mechanism;

FIG. 6 is a partial view similar to that of FIG. 2 showing an alternative embodiment of the invention; and

FIG. 7 is a partial sectional view taken along the line 77 of FIG. 6.

The switch mechanism is mounted in a case consisting of a body and a cover plate 16, the cover plate being removed in FIGS. 2, 3, and 6. A fixed contact 17 is mounted on a conductor 18 having a U-shaped buss clip 19 at the other end. Housings 2t}, 21 are formed in the body 15 for receiving the buss clip 19, with the housings being symmetrically positioned with respect to a support boss 22 for the fixed contact. The conductor 18 may be positioned in the body with the fixed contact on the boss 22 and with the buss clip in either of the housings Ztl, 21.

The switch mechanism includes a moving contact 29 carried on a contact arm 33, a pivot arm 31, a switch actuator 32, a finger member 33, a trigger arm 34, a latch lever 35, a latch release member 26, and a thermal trip member 36. In addition, the switch mechanism includes a mounting bracket 49 having a slot 41 therein, a vertical post 42 extending upwardly from the bracket 40, and an L-shaped drop latch 44 having a tongue 4-5 at one end thereof, which is pivotally and releasably receivable within the slot 41 in the mounting bracket 4-0. The bracket 43, post 42 and latch 44 are made of a magnetizable material, such as soft iron. A coil spring 46 may be positioned circumferentially of the short leg of the L- shaped drop latch 44 to bias the latch away from the bracket 40. A flexible conductor 47 is connected between the contact arm 3% and the thermal trip member 36, with the thermal trip member being spot-welded to a conductor 48 fixed in the body by screws 49. A terminal member 50 is fixed to the conductor 48 for receiving an external wire which is fixed in the terminal by a screw 51. Further, in extending between the contact arm 30 and the thermal trip member 36, the flexible conductor 47 is wound in a coil circumferentially of the vertical post 42.

A toggle or overcenter spring 52 is connected between the contact arm 30 and the trigger arm 34, with the trigger arm serving as a fixed reference for the toggle spring during normal operation of the switch, as shown in FIG. 2. However, when the trigger arm 34 is released by the latch lever 35 under current overload conditions, the trigger arm is rotated clockwise by the spring 52, moving the switch to the tripped, open circuit position, as partially shown in FIG. 3. The circuit breaker is reset by moving the finger member 33 to the extreme clockwise position, with an end portion 56 of the finger member engaging the trigger arm 34.

In the preferred form shown herein, the latch release member 26 has an open U-shaped portion 60 at one end and a notched section 61 at the other end. The open U- shaped portion 60 is positioned against an L-shaped boss 62 formed in the case 15, and is slightly pivotal with respect to the boss 62. One leg of the open U-shaped portion 60 is longitudinally receivable within a cylindrical coil spring 63, which spring is mounted on a boss 59 formed in the case 15. The spring 63 serves to bias the latch release member 26 into engagement with the latch 35. A tongue 64 of the latch lever 35 is positioned in the notch 61 when the circuit breaking mechanism is in the neutral position, as shown in FIG. 2. This engagement of the tongue of the latch lever 35 with the notch 61 of the latch release member 26 maintains the switch in the neutral condition so that it may be used as a switch and actuated from off to on and return as desired.

The preferred embodiment herein provides a primary latch lever release mechanism which will insure a swift and positive movement of the switch to the tripped or circuit interrupted position. When the current through the fiexible conductor 47 exceeds a predetermined value,

the drop-latch 44 is attracted to the post 42, moving the latch in a clockwise direction. The clockwise movement of the drop-latch 44 will cause the latch release member 26 to move downward in a counterclockwise direction and out of engagement with the latch lever 35. When the latch lever 35 is disengaged, the trigger arm 34 is free to rotate clockwise, causing the moving contact to move to the tripped or circuit interrupted position.

The thermal trip member 36, which is ordinarily abimetal strip, is provided as a second means for moving the switch mechanism to a tripped or interrupted position. The trip member 36 has an upstanding portion 65 at its free end with an overhanging shoulder 66 positioned for engaging the tip of the latch release member 26. When the current through the switch exceeds a predetermined value for a predetermined time, the thermal member rotates in a counterclockwise direction to cause the shoulder 66 to engage the latch release member 26 and move the latch release member downward out of engagement with the latch lever 35. When the latch lever 35 is disengaged, the trigger arm 34 is free to rotate clockwise, causing the moving contact to move to the tripped or circuit interrupted position, as shown in FIG. 3.

The circuit breaking mechanism is reset from the tripped position to the neutral position by manually moving the finger member 33 to the extreme clockwise position. Engagement of the tip portion 56 of the finger member with the trigger arm 3-4 causes the trigger arm to move to the position shown in FIG. 2. Engagement of the trigger arm with the latch lever 35 causes the latch lever to move to the position of FIG. 2. A spring 68 provides a slight torque urging the latch lever 35 counterclockwise so as to be in position for engagement by the trigger arm during the reset operation. If the latch 44- has been released and the thermal trip member 36 has cooled, the latch release member will be free to move upward and engage the tongue of the latch lever 35 to latch the circuit breaking mechanism.

An alternative embodiment of the tripping mechanism is illustrated in FIG. 6 of the drawing. Herein the latch release member 26 is pivotally positioned against the L-shaped boss 62 by a light spring 69 which provides a slight torque for urging the latch release member upward toward a latch-engaging position.

The tripping mechanism illustrated in FIG. 6 also includes a U-shaped bracket 70 mounted on the casing 15 with the conductor 47 passing through an open central portion thereof. An L-shaped drop latch 72 is pivotally engageable with the top of the U-shaped bracket 70 and a coiled spring 74 may be positioned circumferentially of the short leg of the L-shape to bias the latch away from the bracket. The bracket and latch normally are made of soft iron. A pin 76 is mounted on the casing 15 to limit the movement of the drop latch 72 in the upward direction. The combination of the spring 74 and the pin 76 causes the drop latch 72 to be positioned a consistent distance from the top of the U-shaped bracket 70 each time the switch mechanism is actuated. This arrangement is advantageous in that it insures the same operating conditions each time the electromagnetic bracket is energized.

In actual operation, the alternative embodiment of the. tripping mechanism shown in FIG. 6 will function in a similar manner to that shown in FIGS. 2 and 3. During current overload conditions, the excessive current flowing through the conductor 47 will induce a flux in the U- shaped bracket 76 attracting the drop latch 72 and causing it to rotate in a clockwise direction. The clockwise movement of the drop latch 72 will partially compress the spring 74 and cause the latch release member 2-6 to rotate in a counterclockwise direction, thereby releasing the latch lever 35.

Although exemplary embodiments of the invention have been disclosed and discussed, it will be understood, that other applications of the invention are possible and that the embodiments disclosed may be subjected to various changes, modifications and substitutions without necessarily departing from the spirit of the invention as defined by the claims which follow.

I claim as my invention:

1. In a circuit breaker switch having a manually actuated off-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position to automatically interrupt the electrical circuit, the combination of:

a latch release member pivotally mounted adjacent one end thereof and engageable with said latch adjacent the other end thereof to hold said latch in a neutral position;

a first trip member engageable with said latch release member adjacent said other end to move said latch release member out of engagement with said latch;

electromagnetic means disposed at and beyond said other end for causing said first trip member to move said latch release member out of engagement with said latch;

a second thermal trip member disposed in general parallel alignment with said latch release member and spaced from said electromagnetic means and engageable with said latch release member to move said latch release member out of engagement with said latch; and

means for energizing said electromagnetic means and said thermal trip member when a current overload passes through said switch, including means for connecting said second thermal trip member in the electrical circuit with a conductor connected in series with said second thermal trip member and passing through said electromagnetic means.

2. In a circuit breaker switch having a manually actuated off-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position to automatically interrupt the electrical circuit, the combination of::

a latch release member engageable with said latch to hold said latch in a neutral position;

a mounting bracket;

a trip member having an L-shape, said trip member being pivotally mounted to said mounting bracket adjacent the end of the long leg of said L-shape and having the end of the short leg of said L-shape engageable with said latch release member to move said latch release member out of engagement with said latch;

a coil spring engaging said trip member, surrounding the short leg of said L-shape thereof, and engaging said latch release member when said latch is in a neutral position and a circuitinterrupted position;

electromagnetic means on said mounting bracket for causing the short leg of said L-shaped trip member to engage said latch release member and move same out of engagement with said latch; and

means for energizing said electromagnetic means when a current overload passes through said switch.

3. In a circuit breaker switch having a manually actuated off-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position to automatically interrupt the electrical circuit, the combination of:

a latch release member engageable with said latch to hold said latch in a neutral position;

a mounting bracket;

a first trip member having an L-shape, said trip member being pivotally mounted to said mounting bracket adjacent the end of the long leg of said L-shape and having the end of the short leg of said L-shape engageabie with said latch release member to move said latch release member out of engagement with said latch;

electromagnetic means on said mounting bracket for causing the short leg of said L-shaped trip member to engage said latch release member and move same out of engagement with said latch;

a second thermal trip member positioned below said latch release member and having an upstanding portion extending above said latch release member and an overhanging shoulder extending laterally from said upstanding portion engageable with said latch release member to move said latch release member downwardly and out of engagement with said latch; and

means for energizing said electromagnetic means and said thermal trip member when a current overload passes through said switch.

4. In a circuit breaker switch having a manually actuated oil-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch having a depending portion and movable between a neutral position and a circuit interrupted position to automatically interrupt the electrical circuit, the combination of:

a latch release member having a notch at one end thereof and the depending portion of said latch engageable with said latch release member and within said notch to hold said latch in a neutral position;

a mounting bracket;

a first trip member having an L-shape, said trip member being pivotally mounted tosaid mounting bracket adjacent the end of the long leg of said L-shape and having the end of the short leg of said L-shape positioned adjacent the depending portion of said latch when in a neutral position and engageable with said latch release member to move said latch release member out of engagement with said latch;

electromagnetic means on said mounting bracket for causing the short leg of said L-shaped trip member to engage said latch release member and move same out of engagement with said latch;

a second thermal trip member positioned below said latch release member and having an upstanding portion extending above said latch release member and through the notch therein, said upstanding portion having an overhanging shoulder engageable with said .latch release member adjacent said notch to move said latch release member downwardly and out of engagement with said latch; and

means for energizing said electromagnetic means and said thermal trip member when a current overload passes through said switch.

5. In a circuit breaker switch having a manually actuated otl-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position to automatically interrupt the electrical circuit, the combination of:

a latch release member engageable with said latch to hold said latch in a neutral position;

a first trip member having an L-shape with one leg thereof engageable with said latch release member to move said latch release member out of engagement with said latch;

electromagnetic means for attracting the other leg of said trip member and moving said one leg into engagement with said latch member;

a compressed coil spring engaging said trip member surrounding said one leg thereof, and engaging said latch release member;

a second thermal trip member engageable with said latch release member to move said latch release member out of engagement with said latch; and

means for energizing said electromagnetic means and said thermal trip member when a current overload passes through said switch.

6. In a circuit breaker switch having a manually actuated elf-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch mo 'ble between a neutral position and a circuit interrupted position to automatically interrupt the electrical circuit, the combination of: s I I a latch release member pivotally'mounted adjacent one end thereof and enageable with said latch adjacent the other end thereof to hold said latch in a neutral position;

a first trip member engageable with said latch release member adjacent said other end to move said latch release member out of engagement with said latch;

electromagnetic means disposed at and beyondsaid other end for causing said first trip member to move said latch release member out of engagement with. said latch, said electromagnetic means comprising a U-shaped member with said first trip member lo' cated. at the open end of the U; second thermal trip member disposed in general parallel alignment with said' latch release member and spaced from said electromagnetic means andten: gageable with said latch release member to move said latch release member out of engagement with said latch; and

means for energizing said electromagnetic means and said thermal trip member when a current overload passes through said switch, including means for connecting said second thermal trip member in the electrical circuit with a conductor connected in series with said second thermal trip member and passing through said U-shaped member.

' 7. In a circuit breaker switch having a manually actuated off-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interruptedtposition to automatically interrupt the electrical circuit, the, combination of:

. a latch release member pivotally mounted adjacent one end thereof and engageable with said latch adjacent the other end thereof to hold said latch in a""neutra l position;

a first trip member engageable with said latch release member adjacent said other end to move said latch release member out of engagement with said latch;

electromagnetic means disposed at and beyond said other end for causing said first trip member to move said latch release member out of engagement with said latch, said electromagnetic means comprising a bracket supporting a post with said first trip member pivoted on said bracket for movement toward and away from said post;

second thermal trip member disposed in general parallel alignment with said latch release member and spaced from said electromagnetic means and engageable with said latch release member to move said latch release member out of engagement with said latch; and

means for energizing said electromagnetic means and said thermal trip member when a current overload passes through said switch, including means for connecting said second thermal trip member in the electrical circuit with a conductor connected in series with said second thermal trip member and wrapped around said post. '4

8. In a circuit breaker switch having a manually actuated off-on switch mechanism and an automatic circuit breaking mechanism mounted in a case the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position to automatically interrupt the electric circuit, the

I combination of:

a latch release member pivotally mounted adjacent one end thereof and engageable with said latch adjacent the other end thereof to hold said latch in a neutral position; a first-trip member engageable with said latch release member adjacent said other end to move said latch release member out of engagement with said latch; i electromagnetic means disposed at and beyond said other end for causing said first trip member to move said latch release member out of engagement with said latch, with said first trip member pivotally engaging said electromagnetic means adjacent one end of said trip member and engaging the latch release member adjacent the other end of said trip member; spring means disposed between said first trip member and said latch release member for urging said members apart;

stop means in said case for limiting movement of said first trip member away from said latch release member;

a second thermal trip member disposed in general parallel alignment with said latch release member and spaced from said electromagnetic means and engageable with said latch release member to move said latch release member out of engagement with said latch; and

means for energizing said electromagnetic means and said thermal trip member when a current overload passes through said switch, including means for con-' necting said second thermal trip member in the electrical circuit with a conductor connected inseries with said second thermal trip member and passing through said electromagnetic means.

References Cited by the Examiner UNITED STATES PATENTS BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner. 

1. IN A CIRCUIT BREAKER SWITCH HAVING A MANUALLY ACTUATED OFF-ON SWITCH MECHANISM AND AN AUTOMATIC CIRCUIT BREAKING MECHANISM MOUNTED IN A CASE, THE AUTOMATIC CIRCUIT BREAKING MECHANISM INCLUDING A LATCH MOVABLE BETWEEN A NEUTRAL POSITION AND A CIRCUIT INTERRUPTED POSITION TO AUTOMATICALLY INTERRUPT THE ELECTRICAL CIRCUIT, THE COMBINATION OF: A LATCH RELEASE MEMBER PIVOTALLY MOUNTED ADJACENT ONE END THEREOF AND ENGAGEABLE WITH SAID LATCH ADJACENT THE OTHER END THEREOF TO HOLD SAID LATCH IN A NEUTRAL POSITION; A FIRST TRIP MEMBER ENGAGEABLE WITH SAID LATCH RELEASE MEMBER ADJACENT SAID OTHER END TO MOVE SAID LATCH RELEASE MEMBER OUT OF ENGAGEMENT WITH SAID LATCH; ELECTROMAGNETIC MEANS DISPOSED AT AND BEYOND SAID OTHER END FOR CAUSING SAID FIRST TRIP MEMBER TO MOVE 